Diagnostic reasoning case · WHO maternal health: MCPC and pre-eclampsia recommendations

Headache in late pregnancy

Most headaches in pregnancy are harmless. A headache after 20 weeks with raised blood pressure is not: it can be the last warning before a fit. Two blood pressure readings and a dipstick decide this in ten minutes.

  • Setting: Health centre with magnesium sulfate, 3 hours by road from the hospital; malaria transmission in the rainy season
  • For midwives, nurses, clinical officers and doctors at first-level facilities
  • Reviewed October 2026

The presentation

Fatima, 22, is in her first pregnancy, 35 weeks by her antenatal card. She has had a headache for 2 days that paracetamol does not help, and this morning her vision became blurred. At her visit at 26 weeks, her blood pressure was 116/72 and her urine was clear.

Taken at triage, the second reading 15 minutes later, seated.
SignValue
Blood pressure164/112 mmHg (repeated: 162/110)
Pulse96 per minute
Breathing rate18 per minute
Temperature36.8 °C
Conscious level (AVPU)Alert

Tests at hand: Urine dipstick · Malaria rapid diagnostic test (RDT) · Blood glucose (finger-prick) · Haemoglobin (Hb)

Starting differential
  • Severe pre-eclampsia Must not missStill possible
  • Eclampsia (imminent) Must not missStill possible
  • Gestational or chronic hypertensionStill possible
  • Malaria (including severe malaria) Must not missStill possible
  • Meningitis or encephalitis Must not missStill possible
  • Migraine or tension headacheStill possible

Work through it

Read each question and decide your own answer first. Then open the model answer and see how the differential changes.

  1. Step 1 of 6 · Look

    Fatima's blood pressure is 164/112. What do you do first, and what does the second reading tell you?

    Model answer

    Check that she is not fitting, unconscious or struggling to breathe: she is alert and talking. Stay with her.

    Repeat the blood pressure correctly: seated, right-size cuff, arm at heart level. Two readings of 160/110 or above after 20 weeks is severe hypertension. Do not wait 4 hours to repeat it, as you would for a reading of 140 to 159 / 90 to 109.

    Both readings are above 160/110. This, with headache and blurred vision, is an emergency even before the dipstick result.

    Never leave a woman with severe hypertension or severe pre-eclampsia alone: a fit can come without warning.
    Differential now
    • Severe pre-eclampsia Must not missLeading (moved up)
    • Eclampsia (imminent) Must not missStill possible
    • Gestational or chronic hypertensionStill possible
    • Malaria (including severe malaria) Must not missStill possible
    • Meningitis or encephalitis Must not missStill possible
    • Migraine or tension headacheLess likely (moved down)
  2. Step 2 of 6 · Ask

    What do you ask? Which answers point to severe pre-eclampsia, and which to another cause?

    Model answer
    • Headache: getting worse, not relieved by regular painkillers?
    • Vision: blurred, flashing lights?
    • Pain in the upper abdomen (epigastric or under the right ribs), nausea or vomiting?
    • Breathlessness; passing less urine?
    • Fever, chills, stiff or painful neck, light hurting the eyes (malaria, meningitis)?
    • Past headaches like this before pregnancy (migraine); epilepsy or past fits?
    • The baby's movements; any bleeding or fluid from the vagina.

    The headache is worse each day and painkillers do nothing. She vomited this morning and has a dull pain under the right ribs. No fever, no neck pain. No headaches like this before, no fits ever. The baby is moving.

    Differential now
    • Severe pre-eclampsia Must not missLeading
    • Eclampsia (imminent) Must not missStill possible
    • Gestational or chronic hypertensionStill possible
    • Malaria (including severe malaria) Must not missStill possible
    • Meningitis or encephalitis Must not missLess likely (moved down)
    • Migraine or tension headacheSet aside for now (moved down)
  3. Step 3 of 6 · Look

    What do you examine, and what does each finding mean?

    Model answer
    • Knee reflexes: brisk reflexes or clonus are a sign of severe pre-eclampsia (and you need a baseline before magnesium sulfate).
    • Upper abdomen: tenderness under the right ribs or in the epigastrium.
    • Lungs: crackles mean fluid in the lungs.
    • Neck stiffness and temperature.
    • Uterus: fundal height, tenderness or hardness, fetal heart.
    • Swelling of the feet is common in pregnancy and is not a reliable sign either way.

    Brisk knee reflexes with 3 beats of clonus at the ankle. Tender under the right ribs. Lungs clear. Neck supple. Fundal height fits 34 weeks; uterus soft; fetal heart 140.

    Differential now
    • Severe pre-eclampsia Must not missLeading
    • Eclampsia (imminent) Must not missStill possible
    • Gestational or chronic hypertensionStill possible
    • Malaria (including severe malaria) Must not missStill possible
    • Meningitis or encephalitis Must not missSet aside for now (moved down)
    • Migraine or tension headacheSet aside for now
  4. Step 4 of 6 · Test

    You have a urine dipstick, malaria RDT, glucose and haemoglobin. Which do you use, and does any result change the immediate plan?

    Model answer
    • Urine dipstick for protein: 2+ or more after 20 weeks with raised BP means pre-eclampsia. But if any severe feature is present, diagnose severe pre-eclampsia even without proteinuria.
    • Malaria RDT: in a malaria area, fever, headache and fits in pregnancy can be malaria; she has no fever, but the test is quick.
    • Glucose if she becomes drowsy or fits.
    • Haemoglobin for the referral note.

    Results: protein 3+. RDT negative. Hb 11.6 g/dL. None of these delays treatment: her BP and symptoms already decide it.

    Differential now
    • Severe pre-eclampsia Must not missLeading
    • Eclampsia (imminent) Must not missStill possible
    • Gestational or chronic hypertensionSet aside for now (moved down)
    • Malaria (including severe malaria) Must not missSet aside for now (moved down)
    • Meningitis or encephalitis Must not missSet aside for now
    • Migraine or tension headacheSet aside for now
  5. Step 5 of 6 · Do

    Classify her. What do you give now, and what do you check before each repeat dose?

    Model answer

    BP 160/110 or above after 20 weeks, proteinuria 3+, severe headache, blurred vision, vomiting, right upper abdominal pain and clonus: severe pre-eclampsia.

    • Magnesium sulfate to prevent fits. Intramuscular regimen loading dose: 4 g of 20% solution IV over 5 minutes, then 10 g of 50% solution by deep IM injection, 5 g in each buttock, with 1 mL of 2% lidocaine in the same syringe. Warn her she will feel warm. If you cannot give the full regimen, give the loading dose and transfer.
    • Lower the blood pressure: for example nifedipine immediate-release 5 to 10 mg by mouth, repeated after 30 minutes if not enough (maximum 30 mg in the acute phase); or labetalol or methyldopa, per your protocol. Aim below 160/110 without dropping it too far.
    • Before any repeat magnesium dose: breathing at least 16 per minute, knee reflexes present, urine at least 30 mL per hour over 4 hours. If not, delay or withhold.
    • Keep calcium gluconate 1 g (10 mL of 10%) ready: given IV slowly over 3 minutes if breathing stops, with ventilation.
    • Lie her on her left side; IV line; record BP, breathing, reflexes and fetal heart often.
    Differential now
    • Severe pre-eclampsia Must not missLeading
    • Eclampsia (imminent) Must not missLess likely (moved down)
    • Gestational or chronic hypertensionSet aside for now
    • Malaria (including severe malaria) Must not missSet aside for now
    • Meningitis or encephalitis Must not missSet aside for now
    • Migraine or tension headacheSet aside for now
  6. Step 6 of 6 · Do

    How do you transfer her safely?

    Model answer
    • She must give birth soon, in a hospital that can do so: arrange transport now.
    • A health worker who can manage a fit travels with her, with magnesium sulfate, a syringe, calcium gluconate and the antihypertensive.
    • If she fits: protect her from injury, turn her on her left side, keep the airway open, and give 2 g of 50% magnesium sulfate IV over 5 minutes (if she fits again 15 minutes after the loading dose). Treat any woman who fits in pregnancy as eclampsia until proved otherwise.
    • Referral note: BP readings and times, proteinuria, symptoms, every dose with its time, fetal heart.
    • After the birth, BP and symptoms are watched closely: eclampsia can happen after delivery.

    Your blood pressure is very high and the headache and blurred sight are warning signs. The injection protects you and the baby from fits. You need to go to the hospital now; your baby may need to be born soon. I will stay with you until you leave.

Must-not-miss conditions

ConditionCluesWhat to do at first-level care
EclampsiaConvulsions with BP 140/90 or above after 20 weeks (a few women have normal BP); coma.Magnesium sulfate, airway, left side, lower severe BP; urgent transfer; birth within 12 hours of the fit.
Severe pre-eclampsia (including HELLP)BP 160/110 or above, or any severe symptom (severe headache, visual change, upper abdominal pain, vomiting, breathlessness, little urine, brisk reflexes or clonus) with raised BP after 20 weeks.Magnesium sulfate, antihypertensive, never alone; urgent transfer for birth.
Severe malariaFever, headache, convulsions, jaundice, coma in a malaria area; positive test.Pre-referral artesunate; urgent transfer.
Meningitis or encephalitisHeadache with fever, stiff neck, light hurting the eyes, confusion.First dose of antibiotic; urgent transfer. If eclampsia cannot be excluded, give magnesium sulfate too.

Decision at first-level care

Fatima has severe pre-eclampsia at 35 weeks: two BP readings of 160/110 or above, proteinuria 3+, severe headache, blurred vision, vomiting, right upper abdominal pain and clonus. She receives a magnesium sulfate loading dose and nifedipine, and is transferred urgently with a health worker for birth.

Source: WHO Managing complications in pregnancy and childbirth (2017); WHO recommendations for prevention and treatment of pre-eclampsia and eclampsia (2011).

Treat here
  • Headache with normal BP, no proteinuria, no fever, no other warning sign: paracetamol, rest, review; return at once if it worsens or vision changes.
Observe and review
  • BP 140 to 159 / 90 to 109 with no symptoms: repeat after 4 hours and test urine before deciding.
  • Gestational hypertension without proteinuria or symptoms: weekly BP, urine and fetal checks.
Refer (urgently, now)This patient
  • BP 160/110 or above, or any severe symptom, with raised BP after 20 weeks: urgently, after magnesium sulfate.
  • Any convulsion in pregnancy or after birth.
  • Pre-eclampsia of any severity, for assessment and a birth plan.
  • Headache with fever and stiff neck, or a positive malaria test with any danger sign.

Key learning points

  • Take the blood pressure of every pregnant woman with a headache; repeat it at once if 160/110 or above.
  • Any severe symptom with raised BP after 20 weeks is severe pre-eclampsia, even without proteinuria.
  • Swelling of the feet is not a reliable sign of pre-eclampsia.
  • Magnesium sulfate prevents and treats eclamptic fits; check breathing, knee reflexes and urine before each repeat dose.
  • Never leave a woman with severe pre-eclampsia alone, and send a skilled companion with her.

Sources

  1. World Health Organization. Managing complications in pregnancy and childbirth: a guide for midwives and doctors, 2nd edition. 2017. Table S-12 differential of headache, blurred vision and convulsions (pre-eclampsia, eclampsia, malaria, meningitis, migraine, epilepsy); severe features; oedema unreliable; treat any fit as eclampsia; Box S-4 and S-5 magnesium sulfate regimen and toxicity checks; calcium gluconate; antihypertensive doses; never leave the woman alone; left side.
  2. World Health Organization. WHO recommendations for prevention and treatment of pre-eclampsia and eclampsia. 2011. Magnesium sulfate as the anticonvulsant of choice; loading dose and transfer where the full regimen cannot be given; antihypertensives for severe hypertension.
  3. World Health Organization. WHO recommendations on antenatal care for a positive pregnancy experience. 2016. Blood pressure and urine testing in antenatal care.
Adapted from WHO guidance; not endorsed by WHO. This page paraphrases and adapts the WHO publications listed under Sources, which are licensed CC BY-NC-SA 3.0 IGO; the adapted text is shared under the same licence for non-commercial education. Reasoning GP is not affiliated with WHO or any other organisation named here. Use it alongside your national guidelines, essential medicines list and formulary, and your clinical judgement. Doses are given only where they come from a WHO source; otherwise follow your national guideline or formulary.